Almost 100 years after its invention, the transistor is regarded by some scientists as one of humanity’s most important inventions, on par with the telephone, light bulb, and bicycle.
Researchers from Linköping University and the Royal Institute of Technology in Sweden have recently announced the successful development of the world’s first wooden transistor.
The world’s first wooden transistor. (Source: PNAS).
Invented nearly a century ago, the transistor is considered by some scientists to be one of the most significant inventions for mankind, comparable to the telephone, light bulb, or bicycle. As an active semiconductor component, it is commonly used as an amplifier or electronic switch. Today, transistors are key components in modern electronic devices and are manufactured at the nanoscale.
The scientific journal PNAS quotes Professor Isak Engquist from the Organic Electronics Laboratory at Linköping University, stating: “We have thought of an unprecedented principle. Yes, the wooden transistor is slower and bulkier, but it works and has great potential for development.”
In previous experiments, wooden transistors could only regulate ion transmission, and when the ions depleted, the transistors ceased to function. However, the transistor developed by Swedish inventors can operate continuously and regulate electric current without wear.
The researchers used balsa wood (scientific name: Ochroma pyramidale, which grows in South America and is considered the lightest wood in the world) to create this new transistor, as the related technology requires a type of wood that is grain-free and has a uniform structure from all angles.
The research team removed lignin from the wooden material and retained only the long, uniform cellulose fibers, with the conduits filled with a conductive polymer known as PEDOT:PSS, which grants this wooden material electrical conductivity.
This sample has been shown to regulate electric current and operate continuously within a selected voltage range. This wooden transistor can also switch the power supply on and off, albeit with significant delays: it achieves a power-off state after 1 second and power-on after 5 seconds.
A major advantage of this transistor is that it can withstand higher current compared to conventional organic transistors, making it potentially useful in various specific applications in the future, such as for regulatory activities in power plants.
